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Date: Tue, 21 Jun 2011 20:40:33 +0300
From: "Michael S. Tsirkin" <mst@redhat.com>
Message-ID: <20110621174033.GB17410@redhat.com>
References: <20110621171044.GA16869@redhat.com>
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In-Reply-To: <20110621171044.GA16869@redhat.com>
Subject: Re: [Qemu-devel] [PATCH] vhost: fix double free on device stop
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To: qemu-devel@nongnu.org, Jason Wang <jasowang@redhat.com>, Juan Quintela <quintela@redhat.com>, Jes.Sorensen@redhat.com

On Tue, Jun 21, 2011 at 08:10:44PM +0300, Michael S. Tsirkin wrote:
> vhost dev stop failed to clear the log field.
> Typically not an issue as dev start overwrites this field,
> but if logging gets disabled before the following start,
> it doesn't so this causes a double free.
> 
> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

Um, this fixed double free but added another one.
Not sure why did it work for me :(
Sent a fixed v2

> ---
>  hw/vhost.c |    4 ++++
>  1 files changed, 4 insertions(+), 0 deletions(-)
> 
> diff --git a/hw/vhost.c b/hw/vhost.c
> index 80f771e..1fbf2e5 100644
> --- a/hw/vhost.c
> +++ b/hw/vhost.c
> @@ -784,5 +784,9 @@ void vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev)
>  
>      hdev->started = false;
>      qemu_free(hdev->log);
> +    if (hdev->log) {
> +        qemu_free(hdev->log);
> +    }
> +    hdev->log = NULL;
>      hdev->log_size = 0;
>  }
> -- 
> 1.7.5.53.gc233e